Paper List

期刊: ArXiv Preprint
发布日期: 2026-03-12
Computational NeuroscienceTheoretical Neuroscience

Formation of Artificial Neural Assemblies by Biologically Plausible Inhibition Mechanisms

Neuroscience Graduate Program, Federal University of Rio Grande do Sul, Brazil | Department of Computer Science, University of Exeter, UK | Department of Computer Science, University of Sheffield, UK | Physics Department, Federal University of Rio Grande do Sul, Brazil

Lucas Hoff, Gustavo Soroka, Matheus Guimarães, Aline Villavicencio, Marco Idiart
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IN SHORT: This work addresses the core limitation of the Assembly Calculus model—its fixed-size, biologically implausible k-WTA selection process—by introducing a dynamic, gamma-oscillation-inspired E%-WTA mechanism and feedforward inhibition, enabling more realistic, self-determined assembly formation and superior retrieval.

核心创新

  • Methodology Proposes the E%-Winners-Take-All (E%-WTA) selection mechanism, inspired by gamma oscillation dynamics, which allows a variable number of neurons to fire based on input strength, replacing the fixed-k selection of the original model.
  • Methodology Integrates a biologically plausible feedforward inhibition mechanism based on the cortical excitatory-inhibitory neuron ratio (e.g., pi=0.2), enhancing network stability and assembly formation.
  • Biology Defines a more rigorous, multi-condition criterion for assembly formation (stationary pattern, synchronization, higher synaptic density), moving beyond the original model's simpler 'no new winners' rule.

主要结论

  • The E%-WTA model with feedforward inhibition (ωinh = -0.2, β ≤ 0.01) successfully forms neural assemblies where size is dynamically determined by network activity, not preset, addressing a key biological limitation.
  • The new model achieves a superior assembly recovery rate (evocation accuracy) compared to the original AC model, demonstrating enhanced functional stability and memory retrieval capability.
  • The introduced formation conditions (stationary pattern, synchronization, higher synaptic density) converge reliably in simulations, providing a robust framework for defining and identifying stable neural assemblies.
研究空白: Existing computational models of neural assemblies, like the Assembly Calculus, often rely on oversimplified, fixed-size selection mechanisms (k-WTA) that fail to capture the dynamic, input-dependent, and power-law-distributed nature of real cortical neural activity governed by oscillatory rhythms like gamma.

摘要: As proposed by Hebb’s theory, neural assemblies are groups of excitatory neurons that fire synchronously and exhibit high synaptic density, representing external stimuli and supporting cognitive functions such as language and decision-making. Recently, a model called Assembly Calculus (AC) was proposed, enabling the formation of artificial neural assemblies through the kk-winners-take-all selection process and Hebbian learning. Although the model is capable of forming assemblies according to Hebb’s theory, the adopted selection process does not incorporate essential aspects of biological neural computation, as neural activity, which is often governed by statistical distributions consistent with power-law scaling. Given this limitation, the present work aimed to bring the model’s dynamics closer to that observed in real cortical networks. To achieve this, a new selection mechanism inspired by the dynamics of gamma oscillation cycles, called E%-winners-take-all, was implemented, combined with an inhibition process based on the ratio between excitatory and inhibitory neurons observed in various regions of the cerebral cortex. The results obtained from our model (called E%-WTA model) were compared with those of the original model, and the analyses demonstrated that the introduced modifications allowed the network’s own dynamics to determine the size of the formed assemblies. Furthermore, the recovery rate of these groups, through the evocation of the stimuli that generated them, became superior to that obtained in the original model.


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